* 13:01 08 December 2008 by Justin Mullins
* For similar stories, visit the Aviation and Invention Topic Guides

A fundamental problem with aircraft is the amount of fuel they have to carry. Designers are forced to make compromises to reduce fuel consumption and to squeeze the necessarily large fuel tanks into the craft. All this drives up cost and reduces manoeuvrability.

One alternative is in-flight refuelling, but that can be logistically difficult as well as dangerous, requiring two aircraft to meet in mid-air and transfer liquid fuel via a flexible hose.

So Taysir Nayfeh and colleagues at Cleveland State University have devised a way of refuelling aircraft using a high-powered laser to recharge on-board batteries.

The team says the aircraft would be fitted with panels capable of converting up to 60% of the laser light that hits them into electricity. A single ground-based laser could then keep numerous aircraft airborne indefinitely.